Rotary impact tool with longitudinal delivering means



Q o 0, 2 M w w J Z M m z @i a w; a .llll fiw I a 4 III I I w w J w a 4 zw L. B. HALVERSON ROTARY IMPACT TOOL WITH LONGITUDINAI. DELIVERING MEANSFiled June 19, 1950 March 31, 1953 Patented Mar. 31, T1953 ROTARY IMPACTTOOL WITH LONGI- TUDINAL DELIVERING MEANS Lloyd B. Halverson, Topeka,Kans.

Application June 19, 1950, Serial No. 169,026

2 Claims. 1

This invention relates tonew and useful im provements in screwdrivers,and relates particu= larly to screwdrivers of the rotary impact type.

The principal object of the present invention is the provision of ascrewdriver so constructed that a hammer blow struck longitudinally ofthe shank thereof will impart both a longitudinal pressure or shock anda rotational force to said shank. This is useful particularly wherescrews or the like are set so tightly that they cannot be loosened byordinary means, or where it is desired to set a screw in a hard materialwhich resists penetration by the screw.

Another object is the provision, in a screwdriver ofJthe classdescribed, of means whereby the cam members which impart the rotaryimpact to the screwdriver shank are automatically returned after eachblow to proper alignment for the next blow.

A further object is the provision of a screwdriver of the classdescribed which is adapted to be used as an ordinary screwdriver withoutad: justment.

Other objects are extreme economy and simplicity of construction,durability, efliciency and dependability of operation, and adaptabilityfor use in connection with wrenches or other similar tools.

With these objects in view, as well as other objects which will appearin the courseof the specification, reference will be had to the drawing,wherein:

Fig. l is a side elevation of a screwdriver embodying the presentinvention, partially broken away. V 1 Fig. 2 is a longitudinal sectionalview'taken on line II-II of Fig. 1.

Fig. 3-isa fragmentary side elevation looking at right angles to thedirection of. view in Fig. 1.

Fig. 4 is a sectional view taken on line IV-IV of Fig. l. I J

Fig. 5 is aplanar layout of a section taken on lineV--V ofFig.4.

Like reference numerals apply to similar parts throughout the severalviews, and the numeral 2 applies to a body member or handle which istubular, having a circular bore 4 formed longitudinally therein, beingopen at its lower end and closed at its upper end to form a head 6suitable for receiving hammer blows. Carried forlongitudinal slidingmovement and axial oscillation in said body member is a bit or shank 8formed of circular rod stock. At its lower end said bit extendsoutwardly from body member 2 and is formed at its outer end to present ascrewdriver angles thereto.

blade In of conventional shape. A helical compression spring I2 iscarried within body member 2,, bearing at one end against the inner endof bit 8 and at its opposite end against head 6. Said spring urges bit 8outwardly at all times.

Bit 8 is operated and retained in body member 2 by a pin l4 fixed insaid bit intermediate the ends thereof and extending radially at rightAs shown, pin [4 is threaded into bit 8, and is provided at its outerend with a screwdriver slot l6, for a purpose hereinafter set forth.Said pin extends into and is contained in a substantially V-shaped slotl8; formed through the wall of body member 2 adjacent the open endthereof. As best shown in Fig. 5, said slot has two upwardly divergentarms 20 and 22, and a connecting portion 24 extending between the loweror closer ends of said divergent arms at right angles to the axis of thetool. All of slot portions 20, 22, and 24 are sufiiciently wide topermit free movement of pin I 4 therein. Each of divergent arms 20 and22 of slot l8 has an upper wall 26 and a lower wall 28, said walls beingadapted to act as cams for turning bit 8 as hereinafter described. Thelower wall of horizontal connecting slot 24 is cut out to present twodownwardly extending spaced apart notches 3t and 32 disposedrespectively in alignment with the lower ends of divergent slot arms 28and 22. Said notches have side walls, parallel to the axis of the tool,and are slightly deeper than half the diameter of pin [4. A tubularcover 34 is disposed about the lower portion of body member 2, cover ingslot I8. At its upper end said cover butts against a shoulder 36 formedin said body mem. her, and it is held releasably in position by a pairof screws 38 extending into the body member. The purpose of said coveris to prevent possible injury to the user should his fingers or a foldof his skin enter slot l8.

The operation of the tool is substantially as follows. The bit 8 isnormally held in its extended position by spring l2, pin [4 resting inone or the other of notches 30 and 32. The drawing shows pin I4 in notch30, this being the setting when it is desired to use the screwdriver forsetting or tightening right-handed screws. The screwdriver may then beused as any ordinary screwdriver, the parallel sides of slot 30retaining pin l4 to prevent axial rotation of bit 8 in the body member.The strength of spring l2 may be such as to prevent the bit from beingmoved. into the body member by the axial pressure exerted on thescrewdriver during normal hand operation. When the screwdriver can nolonger will cause a larger proportion of the momentum to be delivered tothe bit, rather than being expended in rotating the body member. Afterthe momentum of the hammer blow has been exhausted, body member 2 isforced upwardly by spring l2 until slot wall 28 contacts pin [4, saidwall then acting as a cam to rotate said body member on the bit untilnotch 30 again engages pin l4. Pin It is thus automatically reset inproper alignment, with .cam wall 26 after each blow, eliminating thenecessity of resetting the cam members after each blow and permittingrapid operation. When it is desired to loosen a screw, the bit is pushedinto the bodymember slightly and turned so that pin 14 passes throughconnecting slot 24 and comes to rest in notch 32. The pin thencooperates with slot arm 22, and the operation is the same as in slotarm 20, except that the bit will be rotated in the opposite direction.It is believed that the merit of this type of tool lies not only in therotary impact imparted to the bit, but in the simultaneous deliverythereto of both an axial and a rotary impact. The axial impact tends toloosen the screw threads in the work, while the rotary impact turns thescrew.

Although slot [8 is normally covered by cover 34 and the setting of pin[4 is therefore not visible, the setting may be quickly and easily made,or checked, simply by pushing the bit inwardly and turning it in thedirection in which it is desired to turn the screw. Also, it will benoted that slot arms 20 and 22 are of greater width than the diameter ofpin M. This provides that during the upward or return stroke ofbodymember 2, when said pin is riding along the lower wall 28 of one ofslot arms 20 and 22, said pin will be held well away from the entry toconnecting slot 24, thus precluding accidental disturbance of thesetting. i

It is'quite apparent that the invention is not limited to use inconnection with a screwdriver. The outer end of bit 8 could be formed asan impact drill, or for holding socket wrenches or other rotary tools.Also, it might be desirable to insert interchangeable screwdriver bits,or springs of different strengths. For this purpose, the device may bereadily disassembled by first removing cover 34 and then removing pin 14with an ordinary screwdriver. The bit and spring may then be removed,and other tools or springs inserted as desired.

Although I have shown a specific embodiment of my invention, it isapparent that the above 4 described changes and other changes ofconstruction and operation could be made without departing from thespirit of the invention, and it is therefore desired that my patentprotection extend to all subject matter falling properly within thescope of the appended claims.

What I claim as new and desire to protect by Letters Patent is: e

1. A tool of the class described comprising a tubular body member openat one end and having a slot formed in the wall thereof, said slotcomprising two sections inclined relative to the axis of the tool anddivergent away from the open end of the body member and a connectingportion extending at right angles to the axis of the tool andinterconnecting the closer ends of said inclined portions, the wall ofsaid connecting slot I portion closest to the open end of said bodymember having a notch formed therein in alignment with the adjacent endof each of said inclined slot portions, a tool bit carried forrotational and axial sliding movement in said body member and extendingoutwardly from the open end thereof, a work engaging tool carried at theouter end of said bit, resilient means urging said bit outwardly, and amember fixed in said bitand extending radially therefrom into said slot.

2. A tool of the class described comprising a tubular body member openat one end and having a slot formed in the wall thereof, said slotcomprising two sections inclined relative to the axis of the tool anddivergent away from the open end of the body member anda connectingportion extending at right angles to theaxis of the tool andinterconnecting the closer end of said inclined portions, the wall of,said connecting slot portion closest to the open end of said body memberhaving a notch formed therein in alignment with the adjacent end of eachof said inclined slot portions, the side walls of said notches beingparallel with the axis of the tool, a tool bit carried for rotationaland axial sliding movement in said body member and extending outwardlyfrom the open end thereof, a work engaging tool carried at the outer endof said bit, a spring urging said bit outwardly, and a pin fixed in saidbit and extending radially therefrom into said slot.

LLOYD B. HALVERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Italy Sept. 28, 1936

